Building automation systems encompass a wide variety of systems that aid in the monitoring and control of various aspects of building operation. Building automation systems include security systems, fire safety systems, lighting systems, and heating, ventilation, and air conditioning (“HVAC”) systems. Lighting systems and HVAC systems are sometimes referred to as “environmental control systems” because these systems control the environmental conditions within the building.
The elements of a building automation system are widely dispersed throughout a facility. For example, a HVAC system includes temperature sensors and ventilation damper controls as well as other elements that are located in virtually every area of a facility. These building automation systems typically have one or more centralized control stations in which data from the system may be monitored, and in which various aspects of system operation may be controlled and/or monitored. The control station typically includes a computer having processing equipment, data storage equipment, and a user interface. To allow for monitoring and control of the dispersed control system elements, building automation systems often employ multi-level communication networks to communicate operational and/or alarm information between operating elements, such as sensors and actuators, and the centralized control station.
One example of a building automation system control station is the Apogee® Insight® Workstation, available from Siemens Industry, Inc. Building Technologies Division of Buffalo Grove, Ill. (“Siemens”), which may be used with the model Apogee® building automation system, also available from Siemens. In this system, several control stations connected via an Ethernet or another type of network may be distributed throughout one or more building locations, each having the ability to monitor and control system operation.
The typical building automation system (including those utilizing the Apogee® Insight® Workstation) has a plurality of field panels that are in communication with the central control station. While the central control station is generally used to make modifications and/or changes to one or more of the various components of the building automation system, a field panel may also be operative to allow certain modifications and/or changes to one or more parameters of the system. This typically includes parameters such as temperature and otherwise, set port changes, modify a control program, or the like.
The central control station and field panels are in communication with various field devices (the outputs and inputs of which are typically monitored and controlled as “points”). “Field devices” are devices which are operative to measure, monitor, and/or control various building automation system parameters. Example field devices include lights, thermostats, temperature sensors, damper actuators, alarms, HVAC devices, and numerous other field devices as will be recognized by those of ordinary skill in the art. The field devices are in communication with and receive control signals from (and/or send signals to) subsystem controllers, the central control station and/or field panels of the building automation system. Accordingly, building automation systems are able to control various aspects of building operation by controlling and monitoring the field devices.
Buildings utilizing building automation systems typically have numerous field devices that are used for environmental control purposes. These field devices may also be referred to herein as “environmental control devices”. Examples of environmental control devices include thermostats, damper actuators, fans, lights, heaters, and various other devices known to those of ordinary skill in the art. These devices are typically controlled by the building automation system based on conventional parameters, such as a thermostat setting and the sensed temperature or humidity in a room.
Traditional building automation systems monitor the temperature in a room and strive to maintain that temperature at some predetermined level (e.g., as defined by the user at a thermostat). In order to do this, the temperature control system must deliver sufficient cooling and heating to match the actual heat generation in the room, thus resulting in a constant temperature. The actual heat generation in the room is based on a number of factors including the number of occupants in the room, heat generation from physical activities (i.e., sit, stand, walk, run, etc), and heat from other sources within the room such as lighting or equipment, air flow within the room, and various other factors.
Maintaining the temperature in a room at a predetermined level is often sufficient to provide an acceptable comfort level in a room. However, in some situations, the desired temperature in the room may change depending on various factors, such as the actions occurring within the room. For example, an individual that is exercising may prefer the temperature a few degrees cooler than when sitting and reading the paper. In this situation, the individual may temporarily changes the thermostat setting during the exercise time.
While conventional methods for human interaction with a building automation system have been adequate, it would be advantageous to further automate building automation systems to provide comfort control for a space related to the amount of human activity in the space. In particular, it would be advantageous to reduce the required amount of human interaction with the building automation system while still allowing the building automation system to deliver desirable environment conditions for individuals within the building, even if those desired environmental conditions change over time.